Evo Design NEEDS voice recognition, how can it be improved?

[AC Question]

I have an HTC Evo Design currently running a custom rom based on Android 4.0.3. I like the rom very much the issue is that for some reason it is completely lacking in voice recognition. This baffles me due to the fact that the Evo 3D I had previous to this phone (model from about 1 year before the Design came out) did have voice recognition. So... i really need to implement whatever solution is most sensible & practical to give this Evo Design voice recognition capability... IF that is possible. I'm asking what is the issue in terms of either hardware or OS limitations and/or compatibility that are effectively keeping me from having speech recognizer with my current phone configuration?
Thanks!